Start Firefox in Safe Mode to Troubleshoot the issue and to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).

• https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode
• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

I am not using other themes and i have only four addons adblock ,adblock popup blocker,download helper ,ant video downloader thats all but it crashed so many time i think the script error or flash error could cause it to crash

Can you give me your crash reports?

1. Enter about:crashes in the Firefox address bar and press Enter. A Submitted Crash Reports list will appear, similar to the one shown below.
2. Copy the 5 most recent Report IDs that start with bp- and paste them into your response here.

Can you send me your troubleshooting information from the Firefox installation that's having issues? This is a good part in troubleshooting.

• Navigate to about:support via Address Bar
• Click the button that says Copy text to clipboard
• Now, go back to your forum post and click inside the reply box. Press Ctrl+V to paste all the information you copied into the forum post.

bp-4dd22493-09aa-46b4-8249-a9bd42140716 7/16/2014 4:08 PM bp-3dac7bb1-6802-4f86-8cff-26b5b2140716 7/16/2014 2:35 PM bp-540a30e5-57a0-4a8c-9f93-7764a2140716 7/16/2014 12:56 PM bp-29fdbf12-d237-4827-b672-21b8b2140711 7/11/2014 6:12 PM bp-70a77a1c-5fdc-4c85-9c59-49ed32140710 7/10/2014 6:43 PM bp-d39411ff-cd4e-49a8-884a-decb42140710 7/10/2014 4:16 PM bp-80c6dba5-eeb7-4703-9f23-a0dfe2140703 7/3/2014 2:16 PM bp-e81afe02-9372-4e2c-ba19-67fe92140701 7/1/2014 4:07 PM bp-f6acfed7-baac-4dde-9616-16dd02140701 7/1/2014 3:16 PM bp-f87331e7-85c3-4914-a6ee-337d62140701 7/1/2014 3:14 PM bp-f2226c4e-c555-44c2-8cd1-b793b2140701 7/1/2014 2:51 PM bp-de5b3fb2-f7e3-4c3c-9a1b-828e82140701 7/1/2014 2:39 PM bp-7f29276d-e799-48ae-b36d-c68122140701 7/1/2014 2:38 PM bp-f5ed9cf1-9a5c-4be6-8380-9fb3e2140701 7/1/2014 2:38 PM bp-d5e4408c-665f-4024-b6dd-042c22140701 7/1/2014 2:12 PM bp-946062a4-5d5d-4c1c-bb77-acb352140701 7/1/2014 2:11 PM bp-729f53be-0d77-4a70-9983-889812140701 7/1/2014 1:59 PM bp-9b024661-b16f-4de9-a2bd-644202140701 7/1/2014 1:57 PM bp-a4890ad6-eafa-42f9-a17e-586542140701 7/1/2014 1:56 PM bp-454549b3-341c-422e-b2cf-aad122140629 6/29/2014 8:40 PM bp-hr-20140626-398d091d-f2fa-40ca-b756-16141bf7ac0a 6/26/2014 12:48 PM